1. Field of the Invention
The present invention generally relates to a pivot sprinkler which includes an elongate irrigation pipe having sprinklers thereon and rotatable about a central supply pipe and supported by spaced, wheeled towers which are maintained in substantial alignment by a control system.
2. Description of the Prior Art
Pivot sprinklers of the type having an elongate pipe with sprinklers thereon which is supported and propelled around a central standpipe are generally well known and have been used with some degree of success. One of the continuing problems which exist in this type of sprinkler is the retention of the elongate pipe in substantially straight condition as it moves in a circular path about a central standpipe. Various structures have been provided for supporting the elongate pipe and driving the pipe and controlling the relative position of the various supporting units to maintain them in generally aligned condition. This type of pivot sprinkler is typically illustrated in the following U.S. patents:
2,711,615 N. R. Boice, Jr. June 28, 1955 2,807,500 W. Clayton Sept. 24, 1957 3,202,361 D. Kane Aug. 24, 1965 3,355,696 J. Allwood Nov. 28, 1967 3,394,729 C. D. Bower et al. July 30, 1968 3,608,826 R. F. Reinke Sept. 28, 1971 3,680,787 R. M. Sherman Aug. 1, 1972 3,712,544 M. H. Ririe et al. Jan. 23, 1973